After a decade of stagnant wages, professors in the California State University system have lost more purchasing power than other public college faculty in the state and nationwide — a trend that is pushing them out of the middle class, according to a report released Tuesday by the California Faculty Association.

“The CSU stands out,” said Lillian Taiz, a history professor and president of the California Faculty Association, which produced the paper as the first in a series of reports about the system. “No other segment of education in our state or at comparable public universities in the nation allowed faculty to lose ground in the way CSU faculty has.”

After adjusting for inflation, the average faculty pay on each of the 23 campuses slid between 2004 and 2013, according to the report. At San Jose State, it dropped $11,570; for CSU East Bay professors, it fell by $12,500.

By comparison, inflation-adjusted salaries for University of California professors grew over that 10-year period, on every campus — at UC Berkeley, by $4,611 and at UCLA, by $8,402, the report found.

The average salary for CSU faculty — including the many who work on part-time contracts — is $45,000 per year, according to the report. Even if all professors were working on full-time contracts, according to the analysis, the average CSU professor would be making just $63,000.

Average pay for professors at nearly 600 other public, 4-year colleges nationwide also grew after adjusting for inflation, according to the analysis.

A spokeswoman for California State University said the administration was still analyzing the report, but she noted that the figures did not include faculty raises taking effect this academic year.

“It’s not accurate to say the CSU has not invested in its employee groups because it has,” said Laurie Weidner, the system’s spokeswoman. “We’re rebuilding a system that lost $1 billion of its operating budget.”

A three-year contract ratified in November gave all CSU faculty a 1.6 percent pay increase and an additional 3 percent to certain faculty members — about 9,000 employees, according to Weidner. The union and administration will soon resume pay negotiations for the second and third years of the contract, Taiz said.

Katy Murphy is based in Sacramento and covers state government for The Mercury News and East Bay Times, a beat she took on in January 2017. Before that, she was the news organization's higher education reporter, writing about UC, CSU, community colleges and private colleges. Long ago, she covered Oakland schools and other K-12 education issues.